scholarly journals Automatic detection of full ring galaxy candidates in SDSS

2019 ◽  
Vol 491 (3) ◽  
pp. 3767-3777 ◽  
Author(s):  
Lior Shamir
Keyword(s):  
False Positive ◽  
False Positive Rate ◽  
Image Data ◽  
Automatic Detection ◽  
Sloan Digital Sky Survey ◽  
True Negative ◽  
Sky Surveys ◽  
Hubble Sequence ◽  
Positive Rate ◽  
Ring Galaxies

ABSTRACT A full ring is a form of galaxy morphology that is not associated with a specific stage on the Hubble sequence. Digital sky surveys can collect many millions of galaxy images, and therefore even rare forms of galaxies are expected to be present in relatively large numbers in image data bases created by digital sky surveys. Sloan Digital Sky Survey (SDSS) data release (DR) 14 contains ∼2.6 × 106 objects with spectra identified as galaxies. The method described in this paper applied automatic detection to identify a set of 443 ring galaxy candidates, 104 of them were already included in the Buta  + 17 catalogue of ring galaxies in SDSS, but the majority of the galaxies are not included in previous catalogues. Machine analysis cannot yet match the superior pattern recognition abilities of the human brain, and even a small false positive rate makes automatic analysis impractical when scanning through millions of galaxies. Reducing the false positive rate also increases the true negative rate, and therefore the catalogue of ring galaxy candidates is not exhaustive. However, due to its clear advantage in speed, it can provide a large collection of galaxies that can be used for follow-up observations of objects with ring morphology.

scholarly journals Rapid and Automatic Detection of Micronuclei in Binucleated lymphocytes Image

2021 ◽  
Author(s):  
Xiang Shen ◽  
Ying Chen ◽  
Chaowen Li ◽  
Fucheng Yang ◽  
Zhanbo Wen ◽  
...  
Keyword(s):  
False Positive ◽  
Detection Rate ◽  
False Positive Rate ◽  
Research Work ◽  
Estimation Method ◽  
Automatic Detection ◽  
Dose Estimation ◽  
Binucleated Cell ◽  
Positive Rate ◽  
Binucleated Lymphocytes

Abstract In terms of radiation biological dose estimation, the cytokinesis block micronucleus (CBMN) assay is the internationally recognized dose estimation method. Due to the subjectivity and the time-consuming of manual detection, it cannot meet the needs of rapid standard assay of CBMN. Therefore, in this research work, we combined the convolutional neural network to design a software that can be used for rapid standard automatic detection of micronuclei in Giemsa stained binucleated lymphocytes image. The software analysis workflow is divided into four stages: cell acquisition, adhesive cell masses segmentation, cell type identification, micronucleus counting. After verification, our algorithm can quickly and effectively detect binucleated cells and micronucleus even when the cytoplasm is blurred, multiple micronucleus are attached to each other, or micronucleus is attached to the nucleus. In the test of a large number of random images, the software reached 99.4% of the manual detection in terms of the detection rate of binucleated cell, and the false positive rate of binucleated cell was 14.7%. In terms of micronucleus detection rate, the software reached 115.1% of manual detection, and its false positive rate was 26.2%. The analysis time of each picture is about 0.3s, an order of magnitude faster than conventional method.

Machine Learning for Detecting Scallops in AUV Benthic Images

2015 ◽  
pp. 22-40
Author(s):  
Prasanna Kannappan ◽  
Herbert G. Tanner ◽  
Arthur C. Trembanis ◽  
Justin H. Walker
Keyword(s):  
Machine Learning ◽  
False Positive ◽  
Template Matching ◽  
False Positive Rate ◽  
Image Data ◽  
Machine Learning Techniques ◽  
Detection And Counting ◽  
Attractive Option ◽  
Positive Rate ◽  
Histogram Of Gradients

A large volume of image data, in the order of thousands to millions of images, can be generated by robotic marine surveys aimed at assessment of organism populations. Manual processing and annotation of individual images in such large datasets is not an attractive option. It would seem that computer vision and machine learning techniques can be used to automate this process, yet to this date, available automated detection and counting tools for scallops do not work well with noisy low-resolution images and are bound to produce very high false positive rates. In this chapter, we hone a recently developed method for automated scallop detection and counting for the purpose of drastically reducing its false positive rate. In the process, we compare the performance of two customized false positive filtering alternatives, histogram of gradients and weighted correlation template matching.

A 12-Month Clinical Audit Comparing Point-of-Care Lactate Measurements Tested by Paramedics with In-Hospital Serum Lactate Measurements

2018 ◽  
Vol 33 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Kristi L. Swan ◽  
Toby Keene ◽  
Bronwyn J. Avard
Keyword(s):  
False Positive ◽  
Clinical Audit ◽  
Cardiopulmonary Arrest ◽  
Point Of Care ◽  
False Positive Rate ◽  
Tertiary Hospital ◽  
Serum Lactate ◽  
Publication Type ◽  
True Negative ◽  
Positive Rate

AbstractObjectivePrehospital point-of-care lactate (pLA) measurement may be a useful tool to assist paramedics with diagnosing a range of conditions, but only if it can be shown to be a reliable surrogate for serum lactate (sLA) measurement. The aim of this study was to determine whether pLA is a reliable predictor of sLA.MethodsThis was a retrospective study of adult patients over a 12-month period who had pLA measured by paramedics in an urban Australian setting and were transported by ambulance to a tertiary hospital where sLA was measured. Patients were excluded if they suffered a cardiopulmonary arrest at any time, had missing data, or if sLA was not measured within 24 hours of arrival. Levels of agreement were determined using methods proposed by Bland and Altman.ResultsA total of 290 patients were transported with a pLA recorded. After exclusions, there were 155 patients (55.0% male; age 71 [SD=18] years) remaining who had sLA recorded within 24 hours. Elevated pLA (>2.0mMol/L) was associated with sLA measurement (76.1% vs 23.9%; OR 3.18; 95% CI, 1.88-5.37; P<.0001). Median time between measurements was 89 minutes (IQR=75). Overall, median pLA was higher than sLA (3.0 [IQR=2.0] mMol/L vs 1.7 [IQR=1.3]; P<.001). Bland-Altman analysis on all participants showed a mean difference of 1.48 mMol/L (95% CI, -3.34 to 6.31). Normal pLA was found to be a true negative in 82.9% of cases, and elevated pLA was a true positive in 48.3% of cases. When the time between measurements was less than 60 minutes (n=25), normal pLA predicted normal sLA with 100% accuracy, with a false-positive rate of 18.2%. As time between measurements increased, accuracy diminished and the false-positive rate increased.ConclusionsOverall, the level of agreement between pLA and sLA was poor. Accuracy of pLA diminished markedly as the time between the two measurements increased. It may be possible to use pLA as a screening tool; when considered this way, pLA performed much better, though larger prospective trials would be needed to confirm this.SwanKL, KeeneT, AvardBJ. A 12-month clinical audit comparing point-of-care lactate measurements tested by paramedics with in-hospital serum lactate measurements. Prehosp Disaster Med. 2018;33(1):36–42.

The Trans-Neptunian Automated Occultation Survey (TAOS II)

2017 ◽  
Vol 14 (S339) ◽  
pp. 193-196
Author(s):  
M. J. Lehner ◽  
S-Y. Wang ◽  
M. Reyes-Ruiz ◽  
Z-W. Zhang ◽  
L. Figueroa ◽  
...  
Keyword(s):  
Size Distribution ◽  
False Positive ◽  
Focal Plane ◽  
False Positive Rate ◽  
Kuiper Belt ◽  
Image Data ◽  
Direct Imaging ◽  
San Pedro ◽  
Cmos Imagers ◽  
Positive Rate

AbstractTAOS II is a next-generation occultation survey with the goal of measuring the size distribution of the small end of the Kuiper Belt (objects with diameters 0.5–30 km). Such objects have magnitudes r > 30, and are thus undetectable by direct imaging. The project will operate three telescopes at San Pedro Mártir Observatory in Baja California, México. Each telescope will be equipped with a custom-built camera comprised of a focal-plane array of CMOS imagers. The cameras will be capable of reading out image data from 10,000 stars at a cadence of 20 Hz. The telescopes will monitor the same set of stars simultaneously to search for coincident occultation detections, thus minimising the false-positive rate. This talk described the project, and reported on the progress of the development of the survey infrastructure.

Improving diagnosis of acute appendicitis with atypical findings by Tc-99m HMPAO leukocyte scan

2002 ◽  
Vol 41 (01) ◽  
pp. 37-41 ◽  
Author(s):  
S. Shung-Shung ◽  
S. Yu-Chien ◽  
Y. Mei-Due ◽  
W. Hwei-Chung ◽  
A. Kao
Keyword(s):  
Acute Appendicitis ◽  
False Positive ◽  
False Positive Rate ◽  
Accurate Method ◽  
Clinical Findings ◽  
Pathological Findings ◽  
Lower Quadrant ◽  
Predictive Values ◽  
Positive Rate

Summary Aim: Even with careful observation, the overall false-positive rate of laparotomy remains 10-15% when acute appendicitis was suspected. Therefore, the clinical efficacy of Tc-99m HMPAO labeled leukocyte (TC-WBC) scan for the diagnosis of acute appendicitis in patients presenting with atypical clinical findings is assessed. Patients and Methods: Eighty patients presenting with acute abdominal pain and possible acute appendicitis but atypical findings were included in this study. After intravenous injection of TC-WBC, serial anterior abdominal/pelvic images at 30, 60, 120 and 240 min with 800k counts were obtained with a gamma camera. Any abnormal localization of radioactivity in the right lower quadrant of the abdomen, equal to or greater than bone marrow activity, was considered as a positive scan. Results: 36 out of 49 patients showing positive TC-WBC scans received appendectomy. They all proved to have positive pathological findings. Five positive TC-WBC were not related to acute appendicitis, because of other pathological lesions. Eight patients were not operated and clinical follow-up after one month revealed no acute abdominal condition. Three of 31 patients with negative TC-WBC scans received appendectomy. They also presented positive pathological findings. The remaining 28 patients did not receive operations and revealed no evidence of appendicitis after at least one month of follow-up. The overall sensitivity, specificity, accuracy, positive and negative predictive values for TC-WBC scan to diagnose acute appendicitis were 92, 78, 86, 82, and 90%, respectively. Conclusion: TC-WBC scan provides a rapid and highly accurate method for the diagnosis of acute appendicitis in patients with equivocal clinical examination. It proved useful in reducing the false-positive rate of laparotomy and shortens the time necessary for clinical observation.

Predicting Fetal Chromosome Anomalies in the First Trimester Using Pregnancy Associated Plasma Protein-A: A Comparison of Statistical Methods

1993 ◽  
Vol 32 (02) ◽  
pp. 175-179 ◽  
Author(s):  
B. Brambati ◽  
T. Chard ◽  
J. G. Grudzinskas ◽  
M. C. M. Macintosh
Keyword(s):  
Logistic Regression ◽  
General Population ◽  
Likelihood Ratio ◽  
False Positive ◽  
False Positive Rate ◽  
Ratio Method ◽  
Detection Rates ◽  
Gaussian Distributions ◽  
Positive Rate ◽  
Likelihood Ratio Method

Abstract:The analysis of the clinical efficiency of a biochemical parameter in the prediction of chromosome anomalies is described, using a database of 475 cases including 30 abnormalities. A comparison was made of two different approaches to the statistical analysis: the use of Gaussian frequency distributions and likelihood ratios, and logistic regression. Both methods computed that for a 5% false-positive rate approximately 60% of anomalies are detected on the basis of maternal age and serum PAPP-A. The logistic regression analysis is appropriate where the outcome variable (chromosome anomaly) is binary and the detection rates refer to the original data only. The likelihood ratio method is used to predict the outcome in the general population. The latter method depends on the data or some transformation of the data fitting a known frequency distribution (Gaussian in this case). The precision of the predicted detection rates is limited by the small sample of abnormals (30 cases). Varying the means and standard deviations (to the limits of their 95% confidence intervals) of the fitted log Gaussian distributions resulted in a detection rate varying between 42% and 79% for a 5% false-positive rate. Thus, although the likelihood ratio method is potentially the better method in determining the usefulness of a test in the general population, larger numbers of abnormal cases are required to stabilise the means and standard deviations of the fitted log Gaussian distributions.

Identification of and Correction for Publication Bias: Comment

2019 ◽  
Author(s):  
Amanda Kvarven ◽  
Eirik Strømland ◽  
Magnus Johannesson
Keyword(s):  
Publication Bias ◽  
False Positive ◽  
Large Scale ◽  
Meta Analysis ◽  
False Positive Rate ◽  
Effect Sizes ◽  
Replication Studies ◽  
Moderate Reduction ◽  
Positive Rate ◽  
Meta Analyses

Andrews &amp; Kasy (2019) propose an approach for adjusting effect sizes in meta-analysis for publication bias. We use the Andrews-Kasy estimator to adjust the result of 15 meta-analyses and compare the adjusted results to 15 large-scale multiple labs replication studies estimating the same effects. The pre-registered replications provide precisely estimated effect sizes, which do not suffer from publication bias. The Andrews-Kasy approach leads to a moderate reduction of the inflated effect sizes in the meta-analyses. However, the approach still overestimates effect sizes by a factor of about two or more and has an estimated false positive rate of between 57% and 100%.

Characteristics of false-positive alerts on transcranial motor evoked potential monitoring during pediatric scoliosis and adult spinal deformity surgery: an “anesthetic fade” phenomenon

2020 ◽  
Vol 32 (3) ◽  
pp. 423-431 ◽  
Author(s):  
Hiroki Ushirozako ◽  
Go Yoshida ◽  
Tomohiko Hasegawa ◽  
Yu Yamato ◽  
Tatsuya Yasuda ◽  
...  
Keyword(s):  
Spinal Deformity ◽  
False Positive ◽  
Adult Spinal Deformity ◽  
False Positive Rate ◽  
Multivariate Logistic Regression Analysis ◽  
Motor Evoked Potential ◽  
Scoliosis Surgery ◽  
True Negative ◽  
Duration Of Surgery ◽  
Spinal Deformity Surgery

OBJECTIVETranscranial motor evoked potential (TcMEP) monitoring may be valuable for predicting postoperative neurological complications with a high sensitivity and specificity, but one of the most frequent problems is the high false-positive rate. The purpose of this study was to clarify the differences in the risk factors for false-positive TcMEP alerts seen when performing surgery in patients with pediatric scoliosis and adult spinal deformity and to identify a method to reduce the false-positive rate.METHODSThe authors retrospectively analyzed 393 patients (282 adult and 111 pediatric patients) who underwent TcMEP monitoring while under total intravenous anesthesia during spinal deformity surgery. They defined their cutoff (alert) point as a final TcMEP amplitude of ≤ 30% of the baseline amplitude. Patients with false-positive alerts were classified into one of two groups: a group with pediatric scoliosis and a group with adult spinal deformity.RESULTSThere were 14 cases of false-positive alerts (13%) during pediatric scoliosis surgery and 62 cases of false-positive alerts (22%) during adult spinal deformity surgery. Compared to the true-negative cases during adult spinal deformity surgery, the false-positive cases had a significantly longer duration of surgery and greater estimated blood loss (both p < 0.001). Compared to the true-negative cases during pediatric scoliosis surgery, the false-positive cases had received a significantly higher total fentanyl dose and a higher mean propofol dose (0.75 ± 0.32 mg vs 0.51 ± 0.18 mg [p = 0.014] and 5.6 ± 0.8 mg/kg/hr vs 5.0 ± 0.7 mg/kg/hr [p = 0.009], respectively). A multivariate logistic regression analysis revealed that the duration of surgery (1-hour difference: OR 1.701; 95% CI 1.364–2.120; p < 0.001) was independently associated with false-positive alerts during adult spinal deformity surgery. A multivariate logistic regression analysis revealed that the mean propofol dose (1-mg/kg/hr difference: OR 3.117; 95% CI 1.196–8.123; p = 0.020), the total fentanyl dose (0.05-mg difference; OR 1.270; 95% CI 1.078–1.497; p = 0.004), and the duration of surgery (1-hour difference: OR 2.685; 95% CI 1.131–6.377; p = 0.025) were independently associated with false-positive alerts during pediatric scoliosis surgery.CONCLUSIONSLonger duration of surgery and greater blood loss are more likely to result in false-positive alerts during adult spinal deformity surgery. In particular, anesthetic doses were associated with false-positive TcMEP alerts during pediatric scoliosis surgery. The authors believe that false-positive alerts during pediatric scoliosis surgery, in particular, are caused by “anesthetic fade.”

scholarly journals PRATD: A Phased Remote Access Trojan Detection Method with Double-Sided Features

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1894
Author(s):  
Chun Guo ◽  
Zihua Song ◽  
Yuan Ping ◽  
Guowei Shen ◽  
Yuhei Cui ◽  
...  
Keyword(s):  
False Positive ◽  
Detection Method ◽  
False Positive Rate ◽  
True Positive Rate ◽  
Remote Access ◽  
Detection Methods ◽  
Security Threats ◽  
True Positive ◽  
Trojan Detection ◽  
Positive Rate

Remote Access Trojan (RAT) is one of the most terrible security threats that organizations face today. At present, two major RAT detection methods are host-based and network-based detection methods. To complement one another’s strengths, this article proposes a phased RATs detection method by combining double-side features (PRATD). In PRATD, both host-side and network-side features are combined to build detection models, which is conducive to distinguishing the RATs from benign programs because that the RATs not only generate traffic on the network but also leave traces on the host at run time. Besides, PRATD trains two different detection models for the two runtime states of RATs for improving the True Positive Rate (TPR). The experiments on the network and host records collected from five kinds of benign programs and 20 famous RATs show that PRATD can effectively detect RATs, it can achieve a TPR as high as 93.609% with a False Positive Rate (FPR) as low as 0.407% for the known RATs, a TPR 81.928% and FPR 0.185% for the unknown RATs, which suggests it is a competitive candidate for RAT detection.

Sign in / Sign up

Export Citation Format

Share Document